<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    let obj = {a:1,b:{test:1}};
    Object.defineProperty(obj,"b",{
        get(){
            console.log("hahah")
//            return this.b
        },
        set(value){
            this.b = value
        }
    })
    console.log(obj.b)
</script>
</body>
</html>